Magnetic materials suitable for use in relays, ringers, and electro-acoustic transducers such as loudspeakers and telephone receivers characteristically exhibit high values of magnetic coercivity, remanence, and energy product. Among alloys exhibiting such desirable properties are Al-Ni-Co-Fe and Mo-Co-Fe alloys as mentioned, e.g., in U.S. Pat. No. 2,506,624, issued May 9, 1950 to R. E. Wirsching. More recently, alloys comprising Fe, Cr, and Co have been investigated with regard to potential suitability in the manufacture of permanent magnets. Specifically, U.S. Pat. No. 3,806,336, issued Apr. 23, 1974 to H. Kaneko et al., discloses high-cobalt ternary Fe-Cr-Co alloys. Quaternary alloys comprising elements such as, e.g., Nb or Ta in addition to Fe, Cr, and Co are disclosed in U.S. Pat. No. 3,954,519, issued May 4, 1976 to K. Inoue; alloys comprising fourth elements Zr, Mo, Nb, V, Ti, or Al are disclosed in U.S. Pat. No. 4,075,437, issued Feb. 21, 1978 to G. Y. Chin et al.; and lower-cobalt ternary alloys are disclosed in a U.S. patent application by S. Jin, Ser. No. 92,941, filed Nov. 9, 1979 now U.S. Pat. No. 4,253,883.
Powder metallurgy processing of Fe-Cr-Co magnets is disclosed in a U.S. patent application by M. L. Green and R. C. Sherwood, Ser. No. 123,691, filed Feb. 22, 1980.
Magnets are typically mass produced; as a result, final cost is largely determined by cost of raw materials. And, since cobalt has become increasingly expensive as a constituent in Fe-Cr-Co alloys, final cost is strongly dependent on amount of cobalt.